Transmission of Laser Beam Through Tapered Glass Capillaries for Light Microbeams.

The transmission of a laser beam through a tapered glass capillary was investigated both experimentally and theoretically for light microbeams. The transmittances of laser light at 488 and 633 nm through capillaries were measured to be up to 15%, depending on the outlet diameter. By characterizing a real capillary with precise measurement of the whole capillary geometry, a realistic simulation allowed us to calculate the transmittance. By using a Gaussian profile as the input beam in a simulation, the calculated transmittances well reproduced the experimental ones. The density enhancement of the extracted beam was derived and discussed. [ABSTRACT FROM AUTHOR]